Radiator core for automobile cooling systems



March 8, 1932. w w, um 1,848,375

I RADIATOR CORE FOR AUTOMOBILE COOLING SYSTEMS Filed April 27, 1929 4 5 22 /&

Inventm:

WIWZUZIZ'P Gttomeg Patented Mar. s, .1932

WELLINGTON. w. Mum; or Looxronr; NEW YORK- RADIATOR GORE FOR AUTOMOBILE COOLING- SYSTEMS- Application filed A ri 27,

This invention relates to the cores of radiators for the cooling systemsof internal combustion engines or the like and has for its object to provide a more eilicientcon struction which is less costly to manufacture than those heretofore proposed.

lVith these and'other objects in view the invention consists in the novel details of construction andv combinations of parts as will bemore fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanying drawings forming a part of this specification in which like numerals designate like parts in all the vieWs,

Fig. 1 is-afront elevational view somewhat diagrammatic illustrating a radiator for an automobile containing a core and built according to this invention;

Fig. 2 illustrates the assembly of a por tion of a radiator core and including aphrrality of core units, said figure being in ,ver tical detail partly in section to better illustrate the construction, and said figure also including elemental parts goingto make up the assembly;

Fig. 3 is'an elevational View of oneof the core units;

Fig. 4 is a horizontal sectionalviewof a core unit takenas on the line of Figure 3 and looking in the direction of the arrows Fig. 5 isa longitudinal sectional View of one of the core fins taken as on the line 5 5 of Figure 2 and looking in the direction of the arrows; and i i i Fig. 6 is a transverse sectional View of said fin taken as on the line 6+6 of Fig. 5 and looking in the direction of the arrows.

In order that this invention may be the better understood it is said that "heretofore radi'atorcore constructions have been such that either vertical or substantially hori-, zontal water tubes have been formed which permita passage of water therethrough with 7 insuiiicient cooling thereof under some con-- ditions; This has been caused by several, factors such as inadequate dimensions or capacity, insuificient radiating'surface for the transfer of heat from the coolingfluid to the atmosphere, a too direct passage for the cool 1929. Serial no. 358,737. I

is somewhat similar to prior constructions in that the time units are made'fromextre'mely thin metal strips which are preformed by crimping into shapes which will readily fit one another or which will ,fit separator strips provided therefor, all to theend that" the passage of cooling fluid through the ra# diator core will be broken, interrupted, or otherwise afi'ected so that a transfer of more heat to the atmosphere is accomplished be cause of the prolongation of the passage and increased turbulence of the fluid through the tubes of the core. 7

A'still further obj ect. of the invention is to provide a-constructionolfering less resistance but more turbulence to the air passing through the core for absorbing theheat given oil from the cooling fluid. i This invention is particularly applicable to radiators having substantially hexagon ally formed air cells in its core, it being, un-

derstood that other forms may be readily devised Which will still fall within the limits of this iliVeHtiOn. The actual formationof these cells should be described so that the invention may be the better imderstood and therefore the followingis directed to a dis-. closure of such construction.

Extremely thin sheets of soft metal, having high heat conductivity and such for example:

as copper or brass, are formed into narrow strips of about 2 to 3 inches Width. This' strip which is substantially continuous is fed from a rollthrough pressure rollers the sure faces of which constitute dies to impress said strip a plural number of indentions 2 arranged in vertical and horizontal rows the latter-being spaced at appreciable intervals so that, in" its continued passage through the forming machine, the core strip comes in contact with folding dies which pressthe por tions of th'e stripfbetween said rows. These depressed portions are folded or pressed to- 1 ward. each other and the extremities are tightly pinched together at the sides of the strip to form double thickness fins 3 extending laterally from the plane of the major portion of the strip.

The. indentions '2 are substantially of spherical formation and the core strip is so fashioned by the dies that in each row of indentions there is a ridge, or lip, or meeting jointof metal which extends outwardly beyond the fins 3, and the metal forming such ridges has a surface angularity which renders the same as sides of a hexagon. That is to say from Figure 2 it'will be seen that the edges 4 of the core unit are angularly disposed to each other, and the degree of angularity is that between two adjacent sides of a hexagon. The areas 4 extend only about three-sixteenths of an inch from the edge of the unit strip, or for a distance sufficient only for soldering two adjacent strips together.

- The strip so formed is then cut into lengths slightly more than the dimension of the finished core measured from top to bottom thereof. In other words, if the core as completed is to be about twenty-four inches in height then these strips are cut into lengths of about twenty-four and a half inches. The purpose of this is to permit approximately one-quarter inch of each end of the preformed strip to be bent over as clearly indicated in the drawings, the bent over ends of two adjacent strips being soldered or otherwise secured together to form the joint 6 at both the top and the bottom of the radiator core. Two adjacent strips so formedand soldered, with their fins extending inwardly, constitute a radiator core unit and a predetermined number of units are brought together, as shown in Fig. 2, and secured by soldering the interfitting serrated edges 4 to form the finished core possessing the required heat conducting area.

From Fig. 2 it is to be particularly noted that the horizontal rows of indentions 2 are grouped in pairs so that two of said rows occur between two adjacent fins 3. The purpose of this is so that when the two strips of a core unit are assembled the fins will be staggered, each fin fitting the depression between the row pair opposite. It will thus be seen that the fins form portions of the wall structure of the hexagonally shaped air cells 8, the remainder of the core unit forming the other walls of said cells. The vertical rows of indentions 2, when the core units are assembled, constitute tubes 5 to conduct the cooling fluid, such as water, from side to side of the radiator during which travel the heat from said fluid is abstracted and transferred to the air passing through the air cells. The formation of the radiator core unit strips may be readily understood from the foregoing and with reference to prior issued patents such for example as 1,076,364

granted Oct. 21, 1913, to Herbert G. Harrison for hexagonal construction of radiator-cells.

Referring to Fig. 2 there is disclosed a radiator core construction in which a' flat strip of very thin metal is employed which has been previously passed through forming rolls as above described to impress therein the rows of substantially spherical indentions 2 with folds constituting fins 3 separating each pair of horizontal rows of indentions. From Fig.4 it will be observed that in the forming process of the core units there are created flanges 4 at each side edge of the core strip, said flanges having plane surfaces for the purpose of securing one radiator core unit to its adjacent unit. Th at is to say, there are rovided a plurality of these flanges 4 the sur aces of all of which are angularly disposed to each other so that when one unit is brought up against an adjacent unit the flanges of the two units will fit and may be secured together as with solder. The angular displacement of said flanges is such as to form sides of hexagonal air cells 8 as clearly shown in Fig. 2 the coincident indentions of the adjacent units forming the water tubes or passages 5 therebetween.

Radiator constructions are so well known that the'above will be readily understood by one skilled in the art particularly with reference to the drawings, but it might here be stated that these strips when formed and joined as above described, without the interposition of the usual separation strip between the adjacent water tubes, will enable the fins 3 to contactingly rest against and in between the indentions 2 so that as the heated fluid, such as water, courses down the water tube 5 as indicated by the arrows in Fig. 2 the heatfrom said water will be taken up by the thin metal of the core and this heat will be transferred through the fins 3 to the atmosphere which is passing through the spaces 8 known as the air cells of the radiator. In other words, by the foregoing description it will be understood that a core is formed devoid of separator strips or intermediates, said core providing closed water passages 5, and openings 8 for the atmosphere which are not closed at their ends, whereby said atmosphere is free to pass through said spaces and over the surfaces of the metal forming the radiator core.

It is to be observed from Fig. 2 that the adjacent core strips are so cut at their ends andare so assembled that the fins 3 are disposed in staggered relation with each other in each core unit. By this construction the coincident indentions 2 of the adjoining core units are made to assume staggered positions with respect to each other whereby the water in the tube 5 will travel in a zig-zag path instead of in a truly vertical path. This is clearlyindicated by the arrows in Fig. 2 and therefore no further description is deemed necessary except to state that by this "construction not only is the length of the Water column increased from the-top to the bottom of the core but the water while passing through the tube is subjected to a greater turbulence than in constructions heretofore known, whereby an increased transfer of heat tothe metal of vthe core is accomplished,

without unduly restricting the flow through each tube. As a result aohigher mean temperature of the metal of, the entire core is obtained which insures maximum heat trans fer to the air.

Also it is to be observed that the indentions, as clearly'seen in Figs. 2, 3 and 4 are substantially semispherical in form and of a size maximum to one-half the dimension bepair of indentions, as a result of which each r indention-meets or. is tangent to a fin on one side and meets or is tangent to another indentation on the oppositesidathus creating lips which are relatively sharp at the points of tangency and over which the down-flow of water in a tube 5 will cascade particularly in view of the staggered relation of the opposite indentations of said tube (see especially the sectional portion of Fig.

- With reference to Fig. 4 which is a; horizontal sectional view of the parts shown in Fig. 3 it will be seen that should any foreign matter pass over with the coolingfluid.

from the engine and become wedged in any one of the vertical rows of indent-ions 2,

the continued passage ofwater is not affected since the following flow will pass to one side of the obstruction. In other words, by this construction there is provided not only a means of conducting the heated fluid through the core from the top to the bottom thereof, but there is provided additional means of automatically increasing the cooling effect by making the indentions lie in staggered relation with each other. and further there is provided means for permitting the water in its flow from the top to the bottom ofthe core to travel laterally from one vertical pair of indentions to another in a direction from the front to the hack of the radiator whereby the maximum cooling effect is'had. Also it willbe evident from the drawings especially Figs. 2 and l that the air in passing through the core will contact with the spherical walls of the indentions 2 with the result that the aircolumn will be disturbed, broken up, or

otherwise afiected to create a greater turbulence'thereof than if there were no indentions. Therefore there results a greater absorption by the air of the heat from the ingthe watertubes are preferably formed of the metal. In otherjwords the .efiiciency of the heat transfer increases with the depth of metal. I From'actual experiment it has been observed" that these indentions 2 should be of a depth maximum to the elasticity of said indentions, and rapidly falls with a decrease in depth.

In the preceding constructions it should stated that the pre-crimped strips formextremely thin metal, and in practice they aremade ofbrass as well as copper. Each core unit isformed as above described but it should here be stated that each .joint 6 is assembled to form the entire radiator core,-

a clamp is placed around the assembly and pressure applied tohold the parts in tight contacting engagement. The core with the A its encompassing shell and thus made ready for attachment to the automobile chassis.

In Figs. 3 and 4 it will be seen that between the sides of the core unit, inline with each.

horizontal row of indentions, there is formed a raised portion 18 constituting an abutment toadd strength to the core assembly as well as to keep separated the opposite walls of a water tube 5.

In. Figs. 5 and6. are shown respectively a longitudinalv and atransverse section of one of the fins 3, from which it will be seen that, in the forming operation, the ends of each fin are tightly pinched; together as indicated at 14: in Fig. 5 so that upon assembly and soldering of the core units there may be formed a tight joint-19 preventing leakage of water from the tubes 5. However, the portion of the fin intermediate said ends is not subjected to such a pressure whereby there will exist a space 15 between the fin walls into which watweeneach vertical pair there is a ridge, on

lip, or meeting point 21 which does not extend outwardly into the plane of the strip in which the indentions are formed, see Fig. 4. It thus results that when the strips are as sembled a water tube 5 is formed which has ter may pass laterally from the associated.

soldered toclose one wall of the water tube =59 against leakage. After the parts have been closed sides but the intermediate portion of which is freely open as indicated at 22 to permit unobstruct-i've flow of water therethrough. Also by this construction the water tubes can be placed much closer together and therefore increased in number with the result that the flow in gallons per minute through the radiator is increased without diminishing radia- '1 tion.

. because only the thickness of the metal separates the water from the air and the number of water tubes is practically doubled.

In actual application of a radiator as hereinbefore described to an automobile cooling system there has been discovered a greatly increased efiiciency. That is to say as between automobile radiators of the same frontal area, same depth, and same size air cell, one radiator, however, of the best heretofore known efficiency and the other radiator made in accordance with this construcion, it was ascer tained that the latter was at least more efficient in heat dissipation at car speeds increasing from 30 to 65 miles per hour. It is not definitely known just why such a large increase in the efficiency is, obtained but it is believed dependent upon several factors, one being the increase in the number of water tubes 5 together with the elimination of intermediates or separation strips therebetween. Another factor believed prominent in this improvement is the particular formation of the indentions 2, the spherical surfaces of which cause a disturbance, eddying, or other interruption to the air column passing through the cells 8. Together with this last thought is the fact that, due to the elimination of separator strips, the indentions 2 of adjacent core strips lie opposed to each other whereby both lateral sides of the aircolumn are disturbed, or in other words, the molecules of the air column in each cell 8 are doubly agitated, causing an increased turbulence thereof. This last belief is to be given particular credence because of the following test which was actually made on the road, and repeated many times to check the surprising results obtained.

It is well known that radiator cores made of copper have higher heat transferring qualities than cores of same dimensions made of brass, especially at high water temperatures. Two cores were made identically the same except one was of brass and the other of copper and these two cores were subjected to road tests under identical conditions. The

results repeatedly showed that the cooling capacity was substantially the same, or in other words where the copper core was used there was an increase in efiiciency of less than I one per cent over the brass core. This was so surprising that a reason was sought therefor but no scientific one has yet been found. It

7 is firmly believed that with an increase in air turbulence through a radiator core there is an increase in heat transfer. The fins 3 of this construction closely confine the air column to a cell 8, and the opposed spherical indentions 2 of each cell cause such a turbulence of the molecules of the air that the maximum number of said molecules come in contact with the metal walls of the cell. In other words air is a poor conductor of heat but if the air is agitated it becomes commonly known as a better conductor, but this is probably entirely due to the fact that more molecules of the air are positively and directly brought into physical contact with the source of heat.

This invention is not. to be confused with the inventions disclosed in my co-pending applications Serial Nos. 358,735, 358,738 each entitled Radiator core for automobile cooling systems and each filed concurrently herewith. That is to say, in application Serial No. 358,735 there is disclosed a radiator core having square air cells formed by core strips bent around and separated by an intermediate or separator strip which is perfectly plane. In other words, said .separator strip isin its original sheet formation and is inserted between the fins of the core strips and is unsecured to said fins except at the extreme ends thereof. Not only this but positive turbulence is given to the air passing through the air cells due to the spherical formation of said indentations.

According to the invention disclosed in this application, on the other hand, there is provided a core having hexagonally formed air cells instead of square ones. Also the core strips of this application are assembled to form core units which are devoid of any separating strips therebetween whereby a greater number of water tubes is made possible in a core of the same frontal area. Also the fins 3 are so formed that there may be water therein extending in a lateral plane from the main water column whereby a more direct transfer of heat from the water to the metal of the core is made possible through said fins.

In application Serial No. 358,738 there is disclosed a core made up of strips bent around themselves in spaced relation to form core units adapted to receive an intermediate or separator strip in such fashion that hexagonal air cells are produced.

Each strip is'formed with rows of indentions substantially of spherical formation whereby the air in passing through said cells is given a high degree of turbulence. In

\ derstood. It should also be observed that the cent fin and adapted to fluidly communicate separator strip of this application is so cut and distorted that there are actual passages therethrough and should an obstruction occur in one o1 the air cells air from another cell could reach the obstructed cell by passing through said passages.

It is obvious that those skilled in the art may vary the details or" construction and arrangements of parts constituting the article, as well as the steps and combinations of steps constituting the method without departing rom the spirit of the invention and therefore it is not desired to be limited to the foregoing except as may be demanded by the claims.

What is claimed is 1. The herein described radiator unit comprising outer walls formed from a sheet of metal folded to provide a plurality of double walled fins in spaced relation, the-walls of each fin being tightly closed at their ends but spaced therebetween, said sheet between said, fins provided with plural rows of indentions each indention terminating in the adj awith the space between the walls of the adjacent fin as wellas with the adjacent indentions oiisaid rows, the edge portions of said sheet having serrations whereby when two unitsare brought together the serrations of the edge portions of adjoining units will fit and when soldered will form a water tube between said units, the fins of each unit disposed in heat conducting relation against the I metal of the opposite wall and between the T rows of indentions therein.

2. The herein described radiator unit comprising outer walls formed from a sheet of metal folded to provide a plurality of double walled fins in spaced relation, the walls of each finbeing tightly closed at their ends but spaced therebetween, said sheetbetween said fins provided with plural rows of spherical indentions each indention adapted to fluidly communicatewith the space between the walls of the adjacent fin as well as with the adjacent indentions of said rows, the edge portions of said sheet having serrations formed in line with said rows whereby when two units are brought together the serrations of the edge portions of adjoining units will fit and when soldered will form a water tube 'between'said units said indentions so staggereu to cause turbulence in the water assing through'said tube; the fins of each unit disposed in "heat conducting relation against the metal of the opposite wall and be tween the rows of indentions therein.

3. The herein described radiator unit coiiif prising outer walls formed from a sheet of metal folded to provide a plurality of dou blewalled spaced relation, the walls of each being tightly closed at their ends but spaced thereb'e'twe'n,said sheet between said this provided with plural rows of sphericalindentionsarranged parallel toand extending in the direction said'fin's eachi-ndfe'nt-ion adapted to fluidly communicats with the space between the walls of the adjacent fin as well as with the adjacent indentlons of said rows, the edge portions of said sheet having serrations whereby when two units are brought together the serrations of the edge portions of adjoining units will fit and when soldered will form a water tube between said units, the fins of each unlt disposed in heat conducting relation against the metal of the opposite wall and between the rows of indentions therein thereby creating air cells within said units adapted to posi tively break up the column of air passing therethrough. r

4. The herein described radiator comprising a. plurality of units each unit formed from a sheet of metal and provided with opposite walls, said sheet folded to provide clouble walled fins at spaced intervals, the finsof,

one wall alternating with the fins of the other wall, the portion of each wall between said fins being provided with two rows of spherical contacting indentions; and serrated flanges formed along the edges of each "unit interfitting with the flanges of an ad jacent unit to bring the indentions of both units in staggered fluid conducting tube-- forming relation.

5. The, herein described radiator comprising a plurality of units each unit formed from a sheet of metal folded to provide double walled fins at spaced intervals, the portion of the sheet between said fins being provided with spherical contacting indentions, the fins and indentions so arranged that the fins ofone wall of a unit will fit between two rows of indentions of the other wall of said unit; and serrated flanges formed along the edges of each unit, the crown of a serration in line with the middle of an indention,

said flanges interfitting with the flanges of an adjacent unit to bring the indentions of both units in staggered fluid conducting tube-forming relation.

6. A radiator core comprising water tubes, air cells, and heat conducting fins extending from each tube across said cells to an adjacent tube, the walls of each tube having a plurality ofvindentions meeting said fins and extending into said cells, said indentions loo Ill

disposed in staggered relation on opposite sides of said tubes whereby positive turbulence is given the water passing through said tubes. v

7 A radiator core comprisin water tubes; air cells, and heat conducting ns extending from each tube across said cells to an adja-- cent tube, the walls of each tube having a plurality of spherical indentions meeting said fins and each other and extending into said cells, said indentions disposed in staggered relation on opposite sides of said tubes whereby positive turbulence is given the water passing through said tubes.

In testimony whereof I afiix my signature.

WELLINGTON W. MUIR. 

